A distributed sensor/control network is a network of spatially distributed autonomous nodes which include “sensor nodes” (which include one or more sensors) and actuator nodes (which include one or more actuators). A distributed sensor/control network may contain any number of sensor nodes or actuator nodes. Some nodes may include both actuators and sensors (e.g. a sensor which detects the state of the actuator), and thus fall into both the categories of sensor node and actuator node. The actuators are controlled based on the output of the sensors which monitor real-time events/tasks at different locations.
It is known for each sensor node to comprise a wireless transceiver, a microprocessor, a power source, and one or more sensors. The wireless transceiver transmits data to and receives data from other sensor nodes within the network using radio frequency. The microprocessor processes sensor data gathered from the corresponding sensor(s), for example converting analog sensor data to digital sensor data—including signal sampling, signal filtering and/or signal conditioning—before transmitting the processed data onward to the wireless transceiver. In addition, the microprocessor controls functionality of the wireless transceiver and sensor(s) in the sensor node. The power source, for example batteries, is required to power the sensor(s), microprocessor and the wireless transceiver for data acquisition, data processing and data communication. The sensor(s) monitors and tracks changes to a physical condition, for example temperature and pressure, to generate sensor data in the form of analog or digital signals which are then transmitted to the microprocessor for processing. An actuator node similarly comprises a wireless transceiver, a single microprocessor, a power source and one or more actuators. The microprocessor controls the actuator(s) by sending to it control data based on signals received from the transceiver.
The microprocessors of both types of node have to be computationally sophisticated, since they receive data simultaneously from multiple sources, and/or while emitting control data. They therefore typically require bespoke and sophisticated programming, and high computational power. Designing such a network is therefore a complicated and procedure, and implementing it is expensive.